Acne is one of the most common dermatological problems. It tends to affect males and females in adolescence, occasionally persisting into adulthood. Acne occurs mainly on the face in the form of pustules which at times leave permanent scars with undoubted psychological effects on the individual. In physiological terms, acne is to all intents and purposes a chronic skin disease with benign evolution, characterized by an inflammatory process of the hair follicle and of the appended sebaceous gland. The sebaceous gland is rich in lipidic material and is located in the derma at a depth ranging from 0.5 mm to 4 mm from the surface of the skin. The most common pharmacological treatments entail the use of benzoyl peroxide, a powerful antibacterial and keratolytic agent (i.e. able to remove the surface layers of the skin), available in the form of gel at varying concentrations which, however, can cause dermatitis. Azelaic acid has an antibacterial action and is less invasive than benzoyl peroxide but it has long reaction times, ranging from 1 to 4 months. In cases of serious acne, tretinoin is prescribed (e.g. Airol cream), or isotretinoin (Isotrex gel) and/or adapalene (Differin gel), which are synthetic derivatives of vitamin A. This can cause reddening and dryness of the skin, itching and stinging and furthermore increase sensitivity to solar radiation.